LT1370
500kHz High Efficiency
6A Switching Regulator
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FEATURES
DESCRIPTION
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The LT ®1370 is a monolithic high frequency current mode
switching regulator. It can be operated in all standard
switching configurations including boost, buck, flyback,
forward, inverting and “Cuk.” A 6A high efficiency switch
is included on the die, along with all oscillator, control and
protection circuitry.
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Faster Switching with Increased Efficiency
Uses Small Inductors: 4.7µH
All Surface Mount Components
Low Minimum Supply Voltage: 2.7V
Quiescent Current: 4.5mA Typ
Current Limited Power Switch: 6A
Regulates Positive or Negative Outputs
Shutdown Supply Current: 12µA Typ
Easy External Synchronization
Switch Resistance: 0.065Ω Typ
The LT1370 typically consumes only 4.5mA quiescent
current and has higher efficiency than previous parts.
High frequency switching allows for very small inductors
to be used.
New design techniques increase flexibility and maintain
ease of use. Switching is easily synchronized to an external logic level source. A logic low on the Shutdown pin
reduces supply current to 12µA. Unique error amplifier
circuitry can regulate positive or negative output voltage
while maintaining simple frequency compensation techniques. Nonlinear error amplifier transconductance
reduces output overshoot on start-up or overload recovery. Oscillator frequency shifting protects external components during overload conditions.
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APPLICATIONS
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Boost Regulators
Laptop Computer Supplies
Multiple Output Flyback Supplies
Inverting Supplies
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATION
5V to 12V Boost Converter
L1*
VIN
OFF
ON
VOUT†
12V
VSW
FB
S/S
+
LT1370
+
C1**
22µF
25V
GND
C2
0.047µF
R3
2k
VC
R2
6.19k
1%
C4**
22µF
25V
×2
*COILTRONICS
UP2-4R7 (4.7µH)
UP4-100 (10µH)
**AVX TPSD226M025R0200
†MAX I
OUT
L1
IOUT
4.7µH 1.8A
10µH 2A
C3
0.0047µF
LT1370 • TA01
VIN = 5V
L = 10µH
90
R1
53.6k
1%
EFFICIENCY (%)
5V
12V Output Efficiency
92
D1
MBRD835L
88
86
84
82
80
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
LT1370 • TA02
sn1370 1370fs
1